Bis(4,4′-bipyridinium) dodecatungstosilicate 4,4′-bipyridine hexahydrate

The title compound, (C10H10N2)(2)[SiW12O40]center dot C10H8N2 center dot 6H(2)O or (4,4'-bipyH(2))(2)[SiW12O40]center dot(4,4'-bipy)center dot 6H(2)O (4,4'-bipy is 4,4'-bipyridine), was prepared under hydrothermal conditions. The asymmetric unit contains a discrete Keggin-type [SiW12O40](4-) anion (located on a twofold axis), one 4,4'-bipy (located on a twofold axis), two (4,4'-bipyH(2))(2+) cations and six uncoordinated water molecules. The polyoxoanion is constructed from a central SiO4 tetrahedron which shares its O atoms with four trinuclear W3O13 groups, each of which is made up of three edge-sharing WO6 octahedra. The water molecules and [SiW12O40](4-) anions are linked through hydrogen bonds.